In recent years, power generation devices using photovoltaic conversion, such as a photovoltaic cell and a solar cell, sensor devices sensing, for example, temperature and light, and other devices employ photoelectric elements (photoelectric conversion elements).
The photoelectric element includes an electron transport layer, which is required to have high electron transport properties. In the electron transport layer, it is important that energy from the outside generates electrons, and further the area of the reaction interface on which the electrons poured from the outside are reacted is an important factor. Such an electron transport layer has been formed of, for example, a metal, an organic semiconductor, an inorganic semiconductor, an electrically conductive polymer, and an electrically conductive carbon.
For example, in a photoelectric conversion element, the electron transport layer for transporting electrons is formed of an organic substance capable of carrying electrons, such as a fullerene, a perylene derivative, a poly(phenylene vinylene) derivative, and pentacene. This has been improving the electron transport capacity of the electron transport layer, thereby improving the conversion efficiency of the photoelectric conversion element (see Non-Patent Literature 1 for fullerenes, see Non-Patent Literature 2 for perylene derivatives, see Non-Patent Literature 3 for poly(phenylene vinylene) derivatives, and see Non-Patent Literature 4 for pentacene).
A molecular device type solar cell was also reported. In the solar cell, a structure in which an electron-donating molecule (donor) is chemically bonded to an electron-accepting molecule (acceptor) is formed as a thin film on a substrate (see Non-Patent Literature 5).